输入: [4,3,2,7,8,2,3,1] 输出: [5,6]
vector<int> findDisapperedNumber(vector<int>& nums){
nums.push_back(0);
for(int i = 0;i<nums.size(); ++i){
while(nums[i] != nums[nums[i]]){
swap(nums[i], nums[nums[i]]);
}
}
vector<int> ans;
for(int i = 0;i < nums.size(); ++i){
if(i != nums[i]){
ans.push_back(i);
}
}
return ans;
}